We report an integrated nanochannel/nanoelectrode sensor for the detection of DNA using alternating currents. We find that DNA can be detected using platinum as the metal for the detecting electrodes, with a signal to noise ratio exceeding 10. We argue that the signal is at least in part electrochemical in nature, thus holds the promise to yield a sequence-dependent signal. However, we also find that for large voltages, DNA attaches irreversibly to the driving electrodes.